*{
    margin: 0;
    padding: 0;
}
html{
    padding: 20px;
}
li{
    list-style: none;
}
pre{
    font-family: '微软雅黑';
    font-size: 14px;
}
xmp{
    font-family: '微软雅黑';
    font-size: 14px;
}
.red{
    color: red;
}